Process for manufacture of panels made of enameled or vitrified sheet metal designed to be used as covering means for railways, carriages, tramways, automobiles, and the like.



A. MEYER.

PRQCESS FOR MANUFACTURE OF PANELS MADE OF ENAMELED 0R VITRIFIED SHEET METAL DESIGNED TO BE USED AS COVERING MEANS FOR RAILWAYS, CARRIAGES, TRAMWAYS, AUTOMOBILES,-

AND THE LIKE.

APPLICATION FILED JAN. 29, 1913- Patented Apr. 3, I917.

6 i 1 W \x residing at Rue Thimonnier,

ALEXANJDEE MEYER, 0F PARIS, FRANCE.

PEECESS EOE MANUFACTURE OF PANELS MADE OF ENAMELED 0E VI'I'EJIEIEE SEEElEf'l." METAL DESIGNED TO BE USED AS COVERING MEAN S EOE, EAILWAYS, CEEEIAG-Efit, TEAMWAYS, AUTOMOBILES, AND THE-LIKE.

f,22ll,502.

To all whom it may concern." I

Be it known that I, ALExANDRn-Mnvnrz, engineer, citizen of the French Republic,

Paris, Department of the Seine, France, have invented certain newand useful improvements in processes for manufacture of panels made of enameled or vitrified sheet metal designed to be used as covering means for-railways, carriages, tramways, automobiles, and the like, of which the following is a specification. I

This invention relates to improvements in the manufacture of enameled metal plates of the nature or. for the purpose, for example, of those described in an earlier application, Serial Number 676,092.

It has been discovered that one of the chief causes of destruction of enameled plates, particularly when exposed to changes of atmospheric temperature and vibration, is due to a lack of molecular equilibrium between the plate and enamel coating. To overcome this defect and employ an enamel coating solution like that described in the aforesaid application is the object of the present invention.

In the accompanying drawing:

Figure 1 is a sectional view, on an enlarged scale, of a portion of an enameled metal plate produced in accordance with the invention;

Fig. 2 is a similar view illustrating a slight modification.

In both figures of the drawing 1 designates the metal plate, one surface of which is provided with a coating or layer 2 of anti-oxid, or oxid resisting, material of the nature of that described in said prior application, the formula of which is approximately as below having the nearest c0- eficient of expansion to the sheet steel known as Martlnsz Borax 45 parts Quartu 25 forrified flint 5 Feldspar 16 Carbonate of potassium 5 Saltpeter 2.75 Oxid of cobalt 0.25 Ei-oxid of manganese 0.7 5 Oxid of iron 0.25

On this coating 2 are superposed a plu- Specification of Letters Patent.

Patented Apr. 3, rear.

Application filed January 29, 1913. Serial No. 745,047.

rality of layers 4, 5, 6, of enamel, the solutions or mixtures from which the said layers are produced being so constituted that the complete coating comprises alternately arranged relatively hard and relatively soft, or more readily fusible, layers.

For example, the layer/l may be such as will be relatively hard or but slightly fusi ble having the formula of that described in the aforesaid application, namely,

Silicic, acid a; 2.00 Silicate of alumina 1.00 Saline oxid of lead 0.25

Suitable alkali (hydrated borate of sodium, potassium carbonate, or potassium nitrate) 0.15

Rutile 0.015

and the layer 5 will be of relatively soft enamel or have its constituents so proportioned that it has a relatively low melting point. This relatively soft layer may be produced in accordance with the following formula, namely,

Silicic acid e 0,30 Silicate of alumina 2.00 Saline oxid of lead 0.25

-Rutile 0.02

If, as illustrated in Fig. 2, an additional layer 6 is employed this will be similar to the layera, that is, relatively'hard or having a high melting point. lif desired, as illustrated in Fig. 1, a metal reinforcement 3 may be embedded in one of the enamel layers. In preparing the plate according to the method outlined in Fig. 1, thewire trellis 3 would be placed uponthe plate after the anti-oxid layer 2 had been applied thereto. and then the solution for forming the enamel layer 4: poured thereon, such solution passing through all of the interstices in,the strengthening device so that the latter is thoroughly embedded therein.

It will be understood that the de cc of hardness of the enamel layers will epend .upon the proportion of alkali employed in the mixture or solution and as above pointed out the layer can be rendered relatively hard or relatively soft as desired by properly proportioning this element.

Having thus described the invention whatis claimed is I 1. The herein described method of preparingienameled metal plates in which a perfectmolecular equilibrium exists between the metal plate and enamel coating comprising applying to the plate more than two superimposed layers of enamel, the alternate layers being respectively fusible at a relatively high and relatively low temperature.

2. As an article of manufacture, a metal plate coated on one face with enamel, said coating being in molecular equilibrium with the metal of the plate and being formed by an anti-oxid layer applied directly to the metal and more than 'two superposed layers of enamel, the alternate layers being respectively fusible at a relatively high and relatively low temperature.

3. A metal sheet or plate having a surface provided with an enamel coating comprising a surface provided with an enamel coating comprising a plurality of layers, the primary one having a coeflicient of expansion substantially the same as that of the metal sheet, and the superimposed layers being fusible at different temperatures and alternately arranged.

4. A metal sheet or plate having a surface provided with an enamel coating comprising a plurality of layers, alternately fusible at relatively high and relatively low temperatures, and a metal reinforcing means embedded in said coating.

In testimony whereof I aflix my signature in presence of two witnesses.

ALEXANDRE MEYER. 

